[Android] Libvlc: patches to fix TLS errors

[Geoffrey Métais]

vlc-android | branch: master | Geoffrey Métais <geoffrey.metais at gmail.com> | Fri Mar 29 13:51:46 2019 +0100| [08d512a25508f360087e547974b07a49c79c98f7] | committer: Geoffrey Métais

Libvlc: patches to fix TLS errors

> https://code.videolan.org/videolan/vlc-android/commit/08d512a25508f360087e547974b07a49c79c98f7
---

 ...-compat-Workaround-sendmsg-bug-on-android.patch | 81 ++++++++++++++++++++++
 ...work-tls-Handle-errors-from-older-kernels.patch | 39 +++++++++++
 2 files changed, 120 insertions(+)

diff --git a/libvlc/patches/0002-compat-Workaround-sendmsg-bug-on-android.patch b/libvlc/patches/0002-compat-Workaround-sendmsg-bug-on-android.patch
new file mode 100644
index 000000000..ba0578773
--- /dev/null
+++ b/libvlc/patches/0002-compat-Workaround-sendmsg-bug-on-android.patch
@@ -0,0 +1,81 @@
+From a9bf3d0db32407b7320269e33a4864e2977badaf Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Hugo=20Beauz=C3=A9e-Luyssen?= <hugo at beauzee.fr>
+Date: Thu, 28 Mar 2019 15:23:48 +0100
+Subject: [PATCH 1/2] compat: Workaround sendmsg bug on android
+
+This only happens on 64bits builds, see compat/sendmsg.c comments
+---
+ compat/sendmsg.c      | 24 ++++++++++++++++++++++++
+ configure.ac          |  3 +++
+ include/vlc_network.h |  6 ++++++
+ 3 files changed, 33 insertions(+)
+
+diff --git a/compat/sendmsg.c b/compat/sendmsg.c
+index 0f42e782f8..8d69048746 100644
+--- a/compat/sendmsg.c
++++ b/compat/sendmsg.c
+@@ -129,6 +129,30 @@ ssize_t sendmsg(int fd, const struct msghdr *msg, int flags)
+     free(data);
+     return res;
+ }
++#elif defined(__ANDROID__) && defined(__aarch64__)
++
++#undef sendmsg
++
++#include <sys/types.h>
++#include <sys/socket.h>
++
++/**
++ * Since we bumped the NDK version from 14 to 18, some devices (at least up to
++ * Android 6) are returning errors on 4 bytes, even though ssize_t is actually
++ * 8 bytes. This causes `value < 0` checks to yield false, and consider the value
++ * as a non error.
++ * As the patch lies in either the NDK or the Android kernel, or the device libc
++ * we can only work around it. If errno is not 0 & we receive -1, on 32bits or
++ * 64bits, we assume an error was returned.
++ */
++ssize_t vlc_sendmsg(int fd, const struct msghdr *msg, int flags)
++{
++    errno = 0;
++    ssize_t ret = sendmsg(fd, msg, flags);
++    if ((ret < 0 || ret == 0xFFFFFFFF) && errno != 0)
++        return -1;
++    return ret;
++}
+ 
+ #else
+ #error sendmsg not implemented on your platform!
+diff --git a/configure.ac b/configure.ac
+index 49b1166742..6f1edd73a3 100644
+--- a/configure.ac
++++ b/configure.ac
+@@ -365,6 +365,9 @@ AS_IF([test "$SYS" = linux],[
+     ],[
+       HAVE_ANDROID="1"
+       AC_MSG_RESULT([yes])
++      AS_IF([test "${host_cpu}" = "aarch64"], [
++          AC_LIBOBJ([sendmsg])
++      ])
+     ],[
+       AC_MSG_RESULT([no])
+     ])
+diff --git a/include/vlc_network.h b/include/vlc_network.h
+index 184c23acae..6a43fd7d8b 100644
+--- a/include/vlc_network.h
++++ b/include/vlc_network.h
+@@ -290,6 +290,12 @@ static inline void net_SetPort (struct sockaddr *addr, uint16_t port)
+ 
+ VLC_API char *vlc_getProxyUrl(const char *);
+ 
++#if defined(__ANDROID__) && defined(__aarch64__)
++struct msghdr;
++ssize_t vlc_sendmsg(int fd, const struct msghdr *msg, int flags);
++#define sendmsg(a, b, c) vlc_sendmsg(a,b,c)
++#endif
++
+ # ifdef __cplusplus
+ }
+ # endif
+-- 
+2.20.1
+
diff --git a/libvlc/patches/0003-network-tls-Handle-errors-from-older-kernels.patch b/libvlc/patches/0003-network-tls-Handle-errors-from-older-kernels.patch
new file mode 100644
index 000000000..9a7eb736f
--- /dev/null
+++ b/libvlc/patches/0003-network-tls-Handle-errors-from-older-kernels.patch
@@ -0,0 +1,39 @@
+From 22f9fa0c66b78096af08a8f51869bbb24a3768e4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Hugo=20Beauz=C3=A9e-Luyssen?= <hugo at beauzee.fr>
+Date: Fri, 29 Mar 2019 10:56:26 +0100
+Subject: [PATCH 2/2] network: tls: Handle errors from older kernels
+
+If MSG_FASTOPEN is defined, but turns out to be unimplemented by the
+underlying kernel (as is the case on android where the NDK claims to
+support fast open but some older kernels don't) EPIPE is returned
+instead of EOPNOTSUPP.
+See net/ipv4/tcp.c:936 & net/core/stream.c:55
+sk_stream_wait_connect will return EPIPE if no SYN was sent/received,
+and sendmsg will propagate that error.
+Treating EPIPE as a synonym for EOPNOTSUPP here allows for the
+connection to proceed, and the first call to sendmsg to complete as
+expected.
+---
+ src/network/tls.c | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/src/network/tls.c b/src/network/tls.c
+index 56e04d6ce7..3c3c083c30 100644
+--- a/src/network/tls.c
++++ b/src/network/tls.c
+@@ -546,8 +546,11 @@ static ssize_t vlc_tls_ConnectWrite(vlc_tls_t *tls,
+             return -1;
+     }
+     else
+-    if (errno != EOPNOTSUPP)
++    if (errno != EOPNOTSUPP && errno != EPIPE)
++    { /* If MSG_FASTOPEN was defined but the kernel doesn't support fast open at
++        all, EPIPE will be returned instead of EOPNOTSUPP */
+         return -1;
++    }
+     /* Fast open not supported or disabled... fallback to normal mode */
+ #else
+     tls->writev = vlc_tls_SocketWrite;
+-- 
+2.20.1
+